calloc in SwiftHow does any of that relate to Core Graphics? You are simply allocating memory? I'm no swift expert, but the first block of code is allocating a pointer to UInt32 where the next block is just a UInt32. What happens if you say var pixels: UInt32*??

Is laptop external display button OS specific?I had to hit F12 to get to the boot menu so I could boot from USB, but I was still able to use the Fn-F1 combo to display the boot menu to my external monitor. I was then able to run arch live.

From date cannot be nil in Objetive-cIf you're strictly looking for seconds between two dates, then do: NSTimeInterval secondsElapsed = [endDate timeIntervalSinceDate:startDate] But your question is really asking "why can't I get a date from the formatter" :)